As an antenna device such as a parabolic antenna, there is known one disclosed in, e.g., PTL 1. The antenna device disclosed in PTL 1 has a configuration in which a radome is secured to a reflecting mirror by screws or the like and in which a primary radiator that transmits/receives radio waves is disposed in the reflecting mirror. The radome is a dielectric cover attached to an opening face of the antenna.
Further, as disclosed in PTL 2, there is known an antenna device having a configuration in which a radome is attached so as to protrude from the outer circumference of a parabolic reflecting mirror and in which a radiowave absorber for absorbing radio waves is mounted inside the radome. The antenna device disclosed in PTL 2 absorbs leaky waves using the radiowave absorber to improve radiation directivity.